Importing theodolite recordings into QGIS?

Question

I recently mapped an archaeological site using a theodolite (or dumpy level). Therefore, each point recorded has a distance measurement from the theodolite and a degrees off north. I'd like to import this information into QGIS. I know how to import data from Excel but how do I tell QGIS that the one recording is distance and the other direction?

Answer 1

I tried to accomplish the hole procedure within QGIS only, but without proper python knowledge, there is no way I fear.

So I would propose to go the Spreadsheet-way: You need to know the coordinates of your starting point, preferable in a metric system.

I prepared some dummy data from my region in WGS84 UTM 32N in ĹibreOffice Calc (in Excel it should be similar):

id 1 ist the starting coordinate. To generate the next point coordinates from your bearing and distance, you need to enter the formulas into the x and y fields for the second point, and then drag them down for the rest of the points.

=SIN(RAD(B3))*C3+D$2 for x

=COS(RAD(B3))*C3+E$2 for y

In Excel, RAD is RADIANS.

In case you had values where you moved the theodolite to the next point and then resumed measuring, you can simply leave away the $ in the formula, so the new coordinates derive from the new ones before.

In my example, I "measured" points in 10 meters distance, with 60 degree shifts, forming a circle.

You can now export to csv to import the data with Add Delimited Text Layer and create a point layer right away.

My result

Answer 2

In QGIS I'd suggest you have a look at the 'Azimuth and distance' plugin. It's been very useful to me when plotting the results of simple surveys like yours. After installing the plugin you will find it by going: View -> Panels.

Use a projected coordinate system. It's helpful if you know the coordinate for your starting point.

There is also a plugin called the 'Azimuth and distance calculator' which I haven't used, but that might be useful.

N.